Moisture from any source, and contaminants like grease or dirt, can damage welding filler metals and undermine productivity.

Nearly everyone realizes that most jobs sites are far from being clean, dry or orderly—at least for any length of time. Unfortunately, the environmental conditions on the average jobsite can damage welding filler metals, and in turn undermine the operator’s overall productivity, and bottom line. Damaged filler metals, whether they are stick electrodes, flux-cored wire (self-shielded or gas-shielded) or solid wire, can all cause poor weld quality, including porosity, cracking and a host of other weld discontinuities. Singularly or in combination, these issues can lead to expensive and time-consuming rework. But that’s just the beginning.

If filler metals become wet or pick up contaminants from the jobsite, such as dirt, oil, grease, or other substances, they simply and without question need to be replaced. That replacement leads to three costly problems:
1. It causes downtime for changing over the filler metal, particularly welding wires;
2. Filler metal damaged by the environment almost always voids most industry-standard, one-year product warranties;
3. It costs you money—for both the price of the ruined filler metal and for the purchase of new filler metals.

These aren’t merely problems. They hold the potential for raising production costs.

Time for damage control
When filler metals leave the factory they are sealed (usually vacuum-sealed, or hermetically sealed, or wrapped tightly in heavy plastic) and in the best possible condition for the job. Then, it becomes the user’s responsibility to keep them that way, regardless of the harsh job-site conditions. Fortunately, there are some relatively easy steps you can take to accomplish this.

First, you should always use gloves when handling filler metals. Solid wire, in particular, easily picks up moisture from sweaty bare hands. This moisture causes rust to form on the surface of the wire, which in turn leads to poor wire feeding and may create porosity in the finished welds. You can usually tell by a visual inspection of solid wire if it’s been damaged in this way: often the rust mark will be in the exact shape of a handprint! Other types of filler metals won’t show such telltale signs of improper handling, but it is nonetheless important to wear gloves when removing them from their original packaging or preparing them for welding.

Because plasma and oxy-fuel cutting create a significant amount of dust, these processes, which are both common on the jobsite, should be kept clear of filler metals. The cutting dust can accumulate on the surface of flux-cored and solid wires, and cause poor wire feeding. Cutting dust can also clog the contact tip and nozzle in these applications, creating poor electrical conductivity and an unstable or erratic arc. In a stick electrode application, dust can lead to weld porosity. For all of these reasons, it is a good practice to keep cutting activities in a separate area from where welding occurs.

You should also keep filler metals away from water, oil, grease or other similarly damaging elements. Each of these contaminants can lead to poor weld quality, rework and/or welding performance issues that negatively affect productivity on the jobsite. Moisture, especially, can cause hydrogen-induced cracking that must be repaired.

The single most important practice you can implement on a jobsite, however, is to properly store filler metals when they are not in use. First, when flux-cored welding or MIG welding with solid wire, you should cover the welding wire spool with a plastic bag if you plan to leave it on the wire feeder overnight. That is the least you should do.

A better practice involves a few more steps but they are worth the effort to avoid potential welding wire contamination. At the end of the workday, remove the spool from the wire feeder, place it in a clean plastic bag and close it securely. Then place the secured package into the original box and store it in a clean dry area until it is ready to be used again.

As a side note, using an enclosed wire feeder, when possible, is also a good way to protect flux-cored wire and solid wire from harsh jobsite environments. Still this type of feeder will not prevent damage to the filler metal surface if the welding wire is left in the enclosed feeder for any length of time. You should still follow proper handling storage procedures.